channel condition red

Hello, I have an intermittent playback error with our Sony DVW-A500P digi-beta deck. When I try and play a tape there is noticable horizontal picture shift/shake, blocking and constant audio drop out and the deck registers it as a channel condition red error. However, when I sent it in to be repaired the engineer could not replicate these problems, so gave it a general service and cleaned the heads. He also noted that there was only minimal wear on the heads. However, after working for 3 weeks the problem is back, but now realise that turning the deck off for a few hours 'cures' the problem for a while. I'm just wondering what can cause this type of issue, as its not the heads. Apparently older decks had a known fault with their EQ boards but ours is a newer model which should not have this problem. It also had a 3000 hr full service not long ago and nothing was picked up then. Any suggestions welcome!

you have a Ref Video Input problem. This is created multiple ways with a DVW-A500. You MUST have a black signal going into the DVW-A500, as well as the source that you are recording into the DVW-A500 (camera, edit controller, etc.). The Edit controller must be in EXT REF and not internal reference, so it takes its reference from the house black generator.

You can STILL get into trouble, however. If you are using (for example), an AJA Kona product, and a DVW-A500, and everything is locked to external black, if the Kona Control Panel switches itself from EXT REF to VIDEO INPUT, you will create a feedback loop, and the DVW-A500 will give you the red channel condition. You will also get audio distortion, and eventually lose all your audio, and of course, shakey picture.

If you have the problem right now, try this. Your VTR is probabaly hooked up to something right now (in a loop). Perhaps you are on a router, or a patch bay system, or you occationally hook up to an edit controller. Playback the tape, and DISCONNECT ALL INPUTS to the DVW-A500, and make sure that black is going to the REF VIDEO INPUT. I bet you NEVER get a red channel condition error. Now, plug back your inputs, and watch your errors happen.